The use of boldface indicates that across all MLV target regions, a generated sequence read was more similar to the reference than were other XMRV references. Although in this table, PreXMRV1 could be predicted to be present in C3H, LP/J and Mmd1, Xmv43 exhibited higher identity to several breakpoints than the sequences obtained from the mice in this study. Thus, we cannot conclude that any of these mice carry PreXMRV1